h2 lewis structure is the Lewis (electron-dot) representation of the hydrogen molecule, \(\mathrm{H_2}\). It is written as \(\mathrm{H{-}H}\) (or \(\mathrm{H{:}H}\)), where the line (or colon) denotes one shared electron pair.
Valence electrons and the duet rule
Each hydrogen atom has one valence electron. The molecule therefore contains two valence electrons in total, and a stable arrangement places both electrons between the two nuclei. In Lewis-structure language, each hydrogen “counts” the shared pair and reaches a duet (2 electrons in its 1s valence shell).
| Species | Valence electrons per atom | Number of atoms | Total valence electrons |
|---|---|---|---|
| H | \(1\) | \(2\) | \(2\) |
Compact Lewis forms
\(\mathrm{H{-}H}\) and \(\mathrm{H{:}H}\) are equivalent notations for one bonding pair (2 electrons) shared between two hydrogens.
Bond order and formal-charge check
\(\mathrm{H_2}\) contains one single bond, so the bond order is 1. Formal charge on each hydrogen is zero in the Lewis structure because each hydrogen is assigned one electron from the shared pair.
For each H in \(\mathrm{H{-}H}\): \(V=1\), \(N=0\), \(B=2\), so \(\mathrm{FC} = 1 - (0 + 2/2) = 0\).
Visualization of the H2 Lewis structure
Meaning and limitations of the Lewis picture
- Electron-pair bookkeeping: the line indicates two electrons shared between atoms, not a literal rod between nuclei.
- Three-dimensional shape: all diatomic molecules are linear by definition, so no bond-angle construction is needed.
- Orbital detail: the Lewis structure does not show 1s–1s overlap or the bonding/antibonding molecular orbitals; it only encodes connectivity and electron pairs.
Summary statement
\(\mathrm{H_2}\) is correctly drawn as \(\mathrm{H{-}H}\), containing two total valence electrons arranged as one bonding pair that satisfies the duet rule for both hydrogen atoms with formal charges of zero.